To protect different types of systems and devices, such as computers or other electronic equipment, against use by unauthorized individuals, it is known to equip them with some type of access protection. Typical computer access protection includes a user log in. To log in, the user typically enters a user identity and password which checks this information against information stored earlier in order to determine if the user is authorized to use the computer. The disadvantage of this process is that a user must memorize a password which can be difficult since we surround ourselves with many systems which demand a log in process and since these often have different passwords. Many users write down their password, with the consequence that if someone finds the record this person can gain unauthorized access into the system. If the user also has the same password for several different systems, this can have far-reaching consequences.
In the Japanese document JP10222241 “Electronic Pen and System and Method for Individual Authentication”, an electronic pen is described which is equipped with a gyrosensor. When a user writes his signature, the pen senses features of the signature and produces a password by means of an algorithm.
It is also known from WO 99/48268 to replace the PIN code in a mobile communication unit with a signature which the user writes with the communication unit. The communication unit is equipped with a sensor of the gyrosensor or pressure-ball type which senses the movement when the user is writing with the unit.
One problem of the above-mentioned techniques is that a signature is not difficult to forge.